How to install and build C++ gRPC

HI THERE

Here are the official instructions for downloading and building grpc.
However, the following is a more relevant version of how grpc was installed on the ejfat nodes:

1. Setup some environmental variables (assuming bash)

   export GRPC_INSTALL_DIR=/daqfs/gRPC/installation

   export PATH="$GRPC_INSTALL_DIR/bin:$PATH"

   export LD_LIBRARY_PATH="$GRPC_INSTALL_DIR/lib:$LD_LIBRARY_PATH"

   The alternative is to run a provided bash setup script which does the same thing

   /daqfs/gRPC/setupgrpc

2. Clone the repository

   git clone --recurse-submodules -b v1.50 --depth 1 --shallow-submodules https://github.com/grpc/grpc

3. Build the package

   cd grpc

   mkdir -p cmake/build

1. 1. python client libraries:

      pip install prometheus-client

      pip install prometheus-api-client

   2. exporter start up:

      sudo systemctl start prometheus-node-exporter

      sudo systemctl enable prometheus-node-exporter

2. For increased UDP buffer sizes:
   1. For the long term write the following lines into the sysctl.conf file:

      net.core.rmem_max=25000000

      net.core.wmem_max=25000000

   2. To make it immediately effective, execute:

      sudo sysctl -w net.core.rmem_max=25000000

      sudo sysctl -w net.core.wmem_max=25000000

3. To mount /daqfs:
   1. sudo mkdir /daqfs
   2. edit /etc/fstab to include the line:

      dubhe:/raid/daqfs          nfs     rw,bg           0       0

   3. sudo apt-get install nfs-common
   4. sudo mount /daqfs
4. To change one's home directory to /daqfs/home/myUserName:
   1. Edit the /etc/passwd file to include a line something like:

      myUserName:x:2101:1208:John Doe,,,:/daqfs/home/myUserName:/bin/bash

      where 2101 is user id and 1208 is epsci group. Hint: set your user id and group ids on the ejfat nodes to be the same as it is on the computer center machines or there will be an issue when you access files served by computer center like /daqfs/home or /group/...